Safety switch



Patented Oct. 13, 1925.

UNITED STATES OLIVER S. JENNINGS, OF BROOKLYN, NEW YORK, ASSIGNOR TRIO & MANUFACTURING COMPANY, A CORPORATION TO WESTINGHOUSE ELEC- OF PENNSYLVANIA.

SAFETY SWITCH.

Application led September 8, 1920.

To all whom it may concern Be it known that I, OLIVER S. J nNNiNcs, a citizen of the United States, and a resident of Brooklyn, in the county of Kings and State of New York, have invented a new and useful Improvementin Safety Switches, of which the following is a specitication.

My invention relates to switches and particularly to enclosed cut-out switches of the safety type wherein the switch elements are enclosed within a housing and protected by a movable cover which is retained in closed position so long as the switch is included 1n a closed circuit.

One object 'of the invention is to provide a simple, inexpensive and reliable switch mechanism wherein the switch-operatinglever is provided with a simple interlocking device capable of retaining the cover 1n closed position when the switch is closed and releasing the cover When the switch is moved to open position.

Another object is to provide a switch mechanism havin the above characteristics wherein the switc cannot be closed so long as the cover is open, and wherein the closing movement of the cover returns the interlocking device to a position permitting movement of the operating lever to closed position.

Briefly, the invention resides in a simple interlocking device which may be mounted upon the axle of a round-bar operating lever of a well-known type and which consists of a segmental disc mounted upon the axle of the operating lever and having its curved peripheral edge concentric with the axis of rotation. One end ofthe disc is slotted radially and fits into'a portion of the axle which is formed at the point of connection with straight parallel sides. This arrangement prevents relative rotary movement of the disc and axle but permits a radial movement of the disc with respect to the axle. The curved peripheral edge of t-he segmental disc is provided with a flange which is bent normal to the plane of the disc and registers with a clip carried by the cover when the operating lever is in closed position. This ange, however. clears the clip when the disc is moved, by the operating lever, into open position and permits the door to be opened by radial displacement of the disc caused by the spring normally ltending to Serial No. 408,879.

move the disc a "ay from the axle of the operating lever. Radial movement of the disc is controlled by a slot-and-pin mechanism which permits lmovement of the disc radially until the operating lever is moved to open position. lVhen the disc moves radially and opens the cover, one edge thereof engages the cover and prevents movement of the operating lever to closed position so long as the cover remains in open position.

Closing movement of the cover returns the disc to a position wherein the operating' lever is free to move to closed position.

The details of the construction and the advantages incident to the novel arrangement will be apparent upon reference to the accompanying drawings forming a part of the application, wherein Figure l is a plan View of the switch mechanism showing the cover and switch in closed position.

Fig. 2 is a longitudinal vertical section of the apparatus shown in Fig. 1, taken on the line II-II of Fig. 1.

Fig. 3 is a transverse vertical section of the housing taken on the line IIL-III of Fig. 2.

Fig. 4 is an elevational view of a latch clip for retaining the cover in closed position, and

Fig. 5 is an elevational view of an interlocking disc.

Referring to the drawings7 the apparatus includes a housing or cabinet 5 provided, adjacent to one end, with a permanent cover portion 6 having a movable cover or door 7 hinged thereto upon a hinge S which extends transversely of the cabinet. The cover 7 is yieldingly retained in closed position by means of a spring clip 8 that is secured to the cover and which snaps into a recess S provided in the end wall 5.

The switch panel 9 is fastened to the hottom 10 of the housing and consists of a porcelain base 11 upon which is mounted a pair of switch pivot jaws 12, each carrying a` switch-blade member 13 and adapted to be. moved into and out of engagement with the contact-terminal jaws 14. The panel also includes a pair of fuses 15 of the screwplug type which are mounted in suitable receptacles 16 and are adapted to be cut oil' from the live terminals when the switch blades are in open position. The fuses and switch-blade members Y.: `e so located that 3 notched at 23 as `to they are accessible through the opening in the housing for the purpose of inspection and renewal of the fuse, when required, and it is a purpose of this invention to so inter- 5 lock the movable cover or door, which closes the opening in the housing, that access to the interior thereof may not be gained until the switch has been moved to open position or until the current to the fuse receptacles l and accessible parts of the switch has been cut oil".

The switch-blade members 14 are actuated by an operating handle or lever which consists of a one-piece round iron bar 17 provided, at oneend, with a loop or eyelet 18 which serves as a handle. The bar projects through a. bearing 18 provided in one side 'of the housing and is so bent as to rovide the crank shaft 19 which is slipped t rough 20 en eyelet 20 `secured to the switch-blade connecting bar 21.

It will be seen om the foregoing that counterclockwise movement of the o rating handle moves the switch-blade mem rs out of engagement `with the contact members,

slot so engaging the straight .sides of the axle as to preventmlative rotary movement of the disc with respect thereto but permitting relative radial displacement of Athe disc with respect to the operating lever. The

disc is further provided with an angularly disposed slot having a radially disposed wing 26 and a concentrically dis wing 27. This slot is adopted to receive a guide pin 28 which is secured to the side of the 5 housing and prevents radial movement of the disc except when the disc is moved in a position wherein the wi 26 of the angular slot registers with the pm 28. The spring 29, which is attached to the diee at a point 5 adjacent the axle and at the other end to a pin 28, serves to normally exert a foroefupon the disc tending 'to move it radially awayfrom the axle. Such radial displacement of the disc is prevented, however, so long as 5 the pin is registered with the concentric slot 27. The cover or door 7 is provided, on its lower side adjacent the hinge, with a latch clip 30 having a flange 31 projecting toward the adjacent side of the housing. A portion of the curved peripheral edge of the disc 24 is provided with a flange 32 projecting toward the latch cli and the latch clip 30 and the disc or mova le latch member 24 are so relatively positioned that, when the disc 5 occupies the position, indicated in Fig. 2.

whereilthe switch is infilo@ petition, the flanges 31 and 32 overlap and prevent openin movement of the cover.. fl Flil] he. ntheoperatinglenrmmoyedimn position, wherein the mitlvblade members are withdrawn a safe distance from their respective contact jaws, the disc 24 occu ies thewpsition indicated in dotted lines in ig. 2, re'rntli'e Hnge 32 of the disc 24 occu pies a position out of registry with the flange ,-15 i 31. At such time, the door is free to be moved to open osition and the radial slot 2c registers wit che in 2s. The 29 4causes radial movementof the disc 24into eixixga ent with the under. side of the door a t ercby fors the door `into open position the moment the clip B is released, the Y disc occupying, after such movementjthe position indicated b dotiind-dash lirios in Fig. 2. When the isc is in its raised* u tion, closin movementof the operating over is proven by reason of the engagement 'oi the wall of the slot 26 with the pin 28.' The switch cannot, therefore, be 'closed so long as the disc remains in its raised positiom,... When the door is moved to closed position, the disc 24 is depressed linto the position im j dicated yin dotted lines in Fig. 2, in which Y position the disc will permit clockwise rotin-V tion of `the operating lever to closed posi 5 -i tien.

From the foregoing itlwill be seen that, when the switch is in elosedfjposition, door cannot be opened, and *the door` may l, be opened when t e switch has moved 1 a safedietance from the contact ALjaws. It will also .be seen that the switch can not be l closed until after the door hns been closed@ Itis not possible, therefore, tolgain acceseto i the' live switch elements' orcirouits so long l 1; as the switch is in closed position. i

While Lhave described and illustrated but one .embodiment of my invention, it will`be'" apparent tothose skilled in :the srt that mi one changes, modioations, substitutions, ail-5 ditions and omissions my be made in the apparatus described without departing from theapizrit and scope of .the invention, as ser forth .by ihe'appended claims.

I clam as my invention.: 1 115 1. A switch mechanism oomprisingi housing having an opening therein, a mow 1 able oever tor closing the opening, a movlable switch within the housing, a rotatable operatig lever for moving the switch tof open to closed positions, and s. letiel'iii'ig-` member for the cover mounted for rdtatio about the axis of rotation of the operating lever and rotatable with the operating lever for preventing movement oit the operating lever to closed 'tion so long as the cover is in open position andl movable by the cover .f into a position permitting closing movet, ment of the operating lever when the 00m is in ma puni 1 l 2. A switch mechanism comprising a housing having an opening therein, a movable cover for closing the opening, a movable switch within the housing, a rotatable operating lever for moving the switch to open and to closed positions, and latching means for the cover mounted for rotation about the axis of rotation of the operating lever and rotatable with the operating lever for preventing movement of the operating lever to closed position so long as the cover is in open position and movable by the cover into a position permitting closing movement ot the operating lever when the cover is in closed position, the said latching means being adapted to engage the cover and retain it in closed position when the operating lever is in closed position.

3. A switch mechanism comprising a housing having an opening therein, a movable cover for closing the opening, a movable switch within the housing, a rotatable operating lever for moving the switch to open and to closed positions, and late-hing means for the cover mounted for rotation about the axis of rotation of the operating lever and rotatable with the operating lever and movable in a radial direction for preventing movement of the operating lever to closed position so long as the cover is in open position and movable radially by the cover into a position permitting closing movement of the operating lever when the cover is in closed position.

4. A switch mechanism comprising a housing having an opening therein, a movable cover for closing the opening, a movable switch within the housing, a rotatable operating lever for moving the switch to open and to closed positions, a latching means for the cover mounted for rotation about the axis of rotation of the operating lever and rotatable with the operating lever and movable in a radial direction for locking the switch in open position and adapted, when the lever is in closed position, to retain the cover in closed position and, when the lever is in open position, to permit opening movement of the cover, and means for automatically moving the latching member radially to locking position after the cover has moved to open position.

A, switch mechanism comprising a housing having an opening therein, a movable cover for closing the opening, a movable switch within the housing, a rotatable operating lever for moving the switch to open and to closed positions, a latching member for the cover mounted for rotation about the axis of rotation of the operating lever and rotatable with Ithe operating lever and movable in a radial direction for locking the switch in open position and adapted, when the lever is in closed position, to retain the cover in closed position and, when the lever in opcn position, to permit openingr movement of the cover, and means tor automatically moving the latching member radially to locling position after the cover has moved a predetermined distance toward open position.

6. A switch mechanism comprising a housing having an opening therein, a movable c'over Yfor closing the opening, a Inovable switch within the housing, a rotatable operating lever Yfor moving the switch to open and to closed positions, a latching member for the cover mounted for rotation about the axis ot rotation ot the operating lever and rotcxtablc with the operating leverl and movable in a substantiall)T radial direct-ion ttor locking the switch in open position and adapted, when the operating' lever in closed position, to ret-ain the cover in closed position and, when the operating lever is in substantially open posit-ion, to permit opening movement ot the cover, and means 'tor autoimit-ically moving the latching member radially to locking position alter the cover has moved a predetermined d ance toward open posit-ion, the said lat-ching means being adapted, when in switch-loclving position, lto prevent rotation of the lever toward closed position so long as the cover is in ogen position and being operable by the cover into ay position permitting closing; movement of thelever when the cover is moved to closed position.

7. A switch mechanism coinprising a housing havingn an opening therein, a movable cover ior closing the opening, a movable switch within the housing, a rotatable pei-atinglever for moving the switch to open and to closed jositions, a latch clip mounted upon Athe cover, a. latch member mounted for rotation about the axis of rotation of the operating lever and rotatable with the operating lever and movable radially and provided with a flange adapted to register with the latch clip when the operating lever is in closed position and to prevent opening movement of the cover and to clear the said clip when the operating lever is moved to open position, means normally tending to move the hitch member radiallv7 to prevent rotary movement ot the operating levi' while the cover is raised, and means preventing radial movement of the latch member until after the operating lever has moved substantially into open posit-ion.

S. A switch mechanism comprising a housingl having an opening therein, a movable cover tor closing` the opening, a terminal, a switch within the housing to be moved into and out of engagement with the terminal, a. rotatable operating lever movable to open and to closed positions 'tor moving the switch to open and to closed positions, respectively,a latch clip carrifl lll() by the cover, a latch plate rotatable with the operating lever and movable radially with respect thereto for locking the switch in open position and provided with a ange adapted, when the operating lever is in closed position, to register with the said clip and prevent opening movement of the cover and, when the operating lever is in open position, to clear the said clip, a guide pin mounted on the housing, the said latch plate being provided with an angular slot having one Wing radially disposed and the other Wing concentricallv disposed with respect to the axis of the operating lever,

Lamps? through which the said' pin projdcts," a l spring attached, at 'one and, 'to the i and, at the other end, tothe hous'n w ne by the platera moved: radially w en Elie fradial slot is moved -nto registry with the said pin, and means @for moving the sndi'm radial slot into registry with-the pin when the operating levervhas moved to open position to .permit radial movementof the said plate. 

